improve是提示或者提高的意思，而improved则是提升了的意思，区别可以从以下例子看出：
I know you have improved your skills, but it is not enough, you need to keep improve to next level to beat another team. 我知道你已经提高了你的技能，但这还不够，你需要继续提高到一个新的水平来击败另一支球队。
水利万物而不争,
而万物莫能与之争。
